samples: add Terra samples

source: https://github.com/zdevito/terra/tree/master/tests

samples/Terra/sharedlib.t

@@ -0,0 +1,22 @@
+
+
+terra foo(a : int, b : int)
+    return a + b
+end
+
+local ffi =  require 'ffi'
+
+local name = (ffi.os == "Windows" and "foo.dll" or "foo.so")
+
+local args = {}
+
+if ffi.os == "Windows" then
+	args = {"/IMPLIB:foo.lib","/EXPORT:foo" }
+end
+
+terralib.saveobj(name,{ foo = foo }, args)
+
+local foo2 = terralib.externfunction("foo", {int,int} -> int )
+terralib.linklibrary("./"..name)
+
+assert(4 == foo2(1,3))